Year	Percent
1999-01-01	37.1367019674996
2000-01-01	38.8336584347114
2001-01-01	39.9384275749410
2002-01-01	40.7873720084993
2003-01-01	41.6996942064663
2004-01-01	42.6123587400340
2005-01-01	44.3246946252630
2006-01-01	45.2892059193871
2007-01-01	45.8612594233512
2008-01-01	44.9022176954457
2009-01-01	41.5692502074139
2010-01-01	40.5738994654838
2011-01-01	39.7816067549210
2012-01-01	38.0632483234472
2013-01-01	37.1412947975705
2014-01-01	37.7087625833915